This invention relates to a camera, and more particularly to processing of the number of film frames in a camera incorporating therein an electrically erasable/ programmable read-only memory (hereafter referred to as a "EEPROM"). 2. Description of the Related Art
There has heretofore been provided a so-called preparatory winding type camera wherein, after a film as a whole in a patrone is previously wound up, the film is automatically delivered frame after frame each time a shutter release is performed. In the camera of this type, a film count value (the number of film frames) is counted up at the time of the preparatory winding and the count value thereof is counted down by delivery of each frame. Then, when the count value becomes zero, the film is unwound by continuing one frame delivery operation, considering that the photographings by the whole film are completed.
On the other hand, information of camera operation (during the preparatory winding, during one frame delivery, during the unwinding, during the standly and so forth) immediately before the start of the film delivery and immediately after the ending of the film delivery and the number of film frames at the time of the change of the film count value are written into the EEPROM.
The information of the camera operation and the number of film frames which are written into this EEPROM are read out during the processing at the initial stage after the camera becomes operable by the exchange of batteries and the like, whereby the film count value is set and it becomes possible to continue the operations interrupted by the exchange of batteries and the like.
However, in the case of the above-described conventional camera of the preparatory winding type, when the battery is taken out in the middle of one of the frame delivery after the photographing or the film delivery is interrupted due to the wear of the battery, there is a possibility that the final frame enters a photographing preventing region ("S" in the film).
That is, when the shutter release is performed in a state where the film count value showing the remaining amount of the film is "34" for example as shown in FIG. 4, after the photographing is made in this frame, one frame delivery is automatically performed, whereby normally, the count value is counted down to "33" after delivery of one frame.
However, during this one frame delivery, if the battery is withdrawn for example, then one frame delivery is interrupted. At this time, the information of the camera operation stored in the EEPROM indicates "during one frame delivery" and the number of film frames remains as "34".
Thereafter, when the batteries are exchanged, the information of camera operation and the number of film frames, which are stored in the EEPROM, are read out, "34" is set in the film count value and one frame delivery processing interrupted on the basis of the information of camera operation is restarted from the beginning. Then, when one frame delivery processing is completed, the film count value is counted down to be set at "33".
As apparent from FIG. 4, an interval having a length L is formed between the numbers of film frames "34" and "33" due to the above-described frame delivery. As the result, the frame of the film frame number "1" enters "S" of the film. Accordingly, such a problem is presented that, when the film is developed and printed, the frame of the film frame number "1" is cut.